DISCUSSION
This manuscript reports the combined implantation technique (S-ICD+AAE)
that we have been using in a satisfactory manner at our centers in very
high-risk patients over the last 2+ years. To our knowledge, this is the
first report of the combined use of an AAE and S-ICD system in patients
at very high-risk of infection. Although not being explicitly branded
for the S-ICD system, the use of an AAE guarding a S-ICD device was
completely feasible and safe in our cohort. Only little processing of
the current commercially available AAE was needed, without difficult or
lengthy maneuvers that may disrupt the routine or the normal workflow of
a device laboratory. Procedural times and peri-procedural complication
rates were not impacted by this practice, that does not have a learning
curve for proceduralists accustomed by both components of this
procedure. Albeit the cohort being at very high-risk of infection, no
device related infections were observed at one-year and only a single,
conservatively manageable, pocket infection was observed during the
entire follow-up. These authors stand against a routine use of this
combined procedure for all patients undergoing S-ICD placement. A
careful patient selection and a patient-tailored assessment are needed
to maximize the benefits associated with this approach. Nonetheless, it
is our belief that this approach might benefit a niche of very high-risk
of infection patients for which only limited data is available in the
currently published major randomized trials8,9.Figure 1 reports the decisional flow algorithm we have been
using at our institution to select patients potentially suitable for
this combined approach.
A clinical and economical net benefit with the use of an AAE has been
reported in selected patients with TV-ICD and, although previous reports
failed to describe patients at a very high-risk of
infection9, data suggesting that AAE provides value
for the healthcare system by reducing the incidence of CIED infection
could be easily extended to the S-ICD10. If it is true
that infective device-associated complications in patients implanted
with an S-ICD system carry a lower mortality burden, being the
management of those achieved with less invasive and less risky
procedures, they cause patient discomfort and hospitalization for
potential re-intervention is often required11. This
may not pose a severe threat in a fit and young patient, but these
patients at a very high-risk of infections are often frail, in a
compromised systemic condition, and suffer from multiple sever
comorbidities. Therefore, re-hospitalizations and re-interventions carry
a different clinical impact in such a population, who often also shows a
high arrhythmic burden (44% received an appropriate shock during
follow-up) and cannot overlook the need for an ICD. This combined
procedure is exactly aimed at minimizing re-hospitalizations in very
high-risk patients, while helping to maximize the net benefit that the
S-ICD may offer in specific clinical settings. Indeed, although
re-hospitalization costs associated with the management of S-ICD related
complications may be lower than what is observed in TV-ICDs, the device
itself is currently much more expensive (currently billed around 2.5-3x
times its TV-ICD counterpart in our country) and the deployment of an
AAE may help avoiding expensive system replacement, reducing the overall
costs for the healthcare system.